Fix compilation for iOS on XCode 4.5

Compilation directive for PPC was using MAC_OS_X_VERSION_MIN_REQUIRED.

 This is not correct, as the latest SDKs allow to compile for older version of
Mac OS, but don't contain the ppc headers. Changing the directive to use
MAC_OS_X_VERSION_MAX_ALLOWED instead.

 Moreover, uploader.mm was including pwd.h that was not used and doesn't exist
on the latest iOS SDK.
Review URL: https://breakpad.appspot.com/412002

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@982 4c0a9323-5329-0410-9bdc-e9ce6186880e

src/client/mac/handler/minidump_generator.h

@@ -45,7 +45,7 @@
 #include "dynamic_images.h"
 #include "mach_vm_compat.h"
 
-#if !TARGET_OS_IPHONE && (MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_7)
+#if !TARGET_OS_IPHONE && (MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_7)
   #define HAS_PPC_SUPPORT
 #endif
 #if defined(__arm__)

src/client/mac/sender/uploader.mm

@@ -28,7 +28,6 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #import <fcntl.h>
-#import <pwd.h>
 #import <sys/stat.h>
 #include <TargetConditionals.h>
 #import <unistd.h>